Etching

A process of Intaglio printing developed after 1513 whereby a copper plate is heated and covered with a film of wax. As it hardens it forms a Ground over the surface of the plate, which is impervious to acid.

The artist then exposes the copper by drawing an image, through the wax coating, with the use of a needle. The plate is then immersed into a bath of Nitric acid which etches or bites the exposed areas of copper; the process could be repeated numerous times, with new lines being added to create variable depth or a tonal effect.

The longer the plate is exposed to the acid the deeper & broader the lines; when printed these lines will appear darker.

Graduation of tone could also be achieved by stopping out certain areas of the plate, by removing it from the acid, cleaning it and covering the exposed area to be stopped out with varnish. When reintroduced into the acid the stopped out area would cease to be bitten, but the remainder of the exposed lines would continue to be etched. A close inspection of the lines will show that they tend to have a squared end as opposed to the tapered end of an engraving.

The freedom of expression in the drawing made etching a popular medium for artists.

When etched to the artists satisfaction the plate was removed from the acid, cleaned and inked. The ink could be wiped clean from all but the etched lines, or to create a richer tonal effect, a feather or cloth was employed to drag a tiny amount of ink from the etched lines to the plate surface; the effect being known as Retroussage.

Etching was frequently combined with Drypont on a plate in order to empathize particular detail.